1. Field of the Invention
The invention relates to a holding device for plug-in cards of an electrical device comprising a card rack forming a frame-like plug-in connection panel and/or operating panel, on which the plug-in cards are mounted in parallel with one another by means of front plates provided at one of their edges, each front plate carrying at least one plug-in connector and/or one operating or display element which is arranged in the area of an aperture of the card rack which is closed by the respective front plate. A holding device of this type can have a PC format.
2. Description of the Related Art
In recent times, the most essential basic modules of personal computers such as processor, memory and input/output interfaces are used for producing control processors for special purposes. These modules are arranged on so-called plug-in cards with standardized dimensions. The plug-in cards are electrically connected with one another via plug-in connections which are also standardized.
The electrical connection of the plug-in cards to the outside world (screen, keyboard, line connections) or the operation of the device is effected via a front plate arranged at one edge of the plug-in card, on which connecting plugs are arranged and the dimensions of which are also defined. Only the plugs used--the so-called peripheral plugs--are freely selectable. The peripheral plugs or also operating and connecting elements project through apertures in the card rack provided for this purpose and thus form their connecting panel or operating panel. The length and width of the apertures and their position with respect to one another is also standardized.
It is then obvious also to build up the control electronics needed for the above-mentioned special applications on plug-in cards in PC format since a PC card rack is needed in any case for the PC-specific basic modules.
By also using standard PC elements and dimensions for special control systems, there is, however, a risk of a user procuring only the plug-in cards with the special electronics and using these in a commercially available PC. The manufacturer of the special control systems is then deprived of the reward for his efforts which he has expended to adapt the entire control system and not only the special electronics to the specific circumstances.